改性木屑吸附除亚甲基蓝性能

为提高对亚甲基蓝的去除效果,采用热解+NaOH浸泡方法制备了改性木屑,用SEM研究了改性对木屑表面结构的影响,并以该改性木屑为吸附剂,进行了从水溶液中吸附亚甲基蓝的性能研究。研究结果显示,改性木屑表面光滑,并出现多发熔孔。常温下,改性木屑对亚甲基蓝的吸附等温线符合Langmuir方程,最大吸附量322.58 mg/g,是原始木屑的10倍,是活性炭的3倍,改性效果显著;对浓度为200 mg/L、pH值为7的亚甲基蓝溶液,改性木屑投加量为0.8 g/L时,去除率达到了99.01%,去除效果理想。吸附动力学符合伪二级速率方程。     

电极改性对电极生物膜反硝化反应器硝酸盐氮去除性能的影响

探究在碳纤维毡电极上利用恒电压电化学聚合聚吡咯(PPy)的聚合效果,并利用傅里叶变换红外线(FTIR)及扫描电镜(SEM)对其进行表征;将聚吡咯覆膜改性后的碳纤维毡电极应用到自养反硝化的电极生物膜反应器(BER)中,考察电极改性对自养反硝化电极生物膜反应器的硝酸盐氮去除性能影响,并研究电极改性对生物膜附着量及生物膜微生物群落的影响。结果表明,恒电压电化学聚合能够在碳纤维电极表面形成均匀稳定的聚吡咯膜,从而实现聚吡咯在炭纤维毡电极上的覆膜改性。改性后的电极应用到自养反硝化电极生物膜反应器中,可使反应器对NO3--N的去除效率由对照反应器的67.3%增加到83.9%,处理效果提高了24.7%。对反应器内电极生物膜进行生物量测定和扫描电镜分析,可以看到R2反应器中改性电极生物膜附着量明显多于R1反应器中未改性电极生物膜的附着量,说明电极改性有利于生物膜的附着。电极生物膜微生物16S rDNA分析中R1反应器电极生物膜菌落组成中优势菌属为Dechloromonas sp.,而R2反应器电极生物膜的优势菌为Hydrogenophaga sp.(噬氢菌属)和Thauera sp.(陶厄氏菌属),两者有明显差别,并且R2反应器比R1反应器生物膜的菌落组成更多样化,这说明电极材料的改性对电极生物膜微生物群落的组成产生了影响。     

改性粉煤灰合成沸石对甲基橙的吸附动力学

以粉煤灰(FA)为原料,采用水热晶化一步法制备了NaP1型沸石(ZFA),对合成产物的结构进行了表征,并采用阳离子表面活性剂十六烷基三甲基溴化铵(CTAB)对其进行改性。通过静态吸附实验,研究了改性后NaP1型沸石(MZFA)对水溶液中甲基橙的吸附特性,从动力学角度探讨了吸附机理。结果表明,在所研究的浓度条件下,改性NaP1型沸石对甲基橙的吸附符合Langmuir等温吸附方程,在25℃时,静态饱和吸附量(Qm)为64.76 mg/g。动力学分析表明,改性NaP1型沸石对溶液中甲基橙的吸附符合准二级动力学模型。     

Integrated model of simulated occupant injury risk and real medical costs

Introduction

The purpose of this study was to develop an integrated methodology that links occupant injury risk functions, estimated in the laboratory, with real world medical treatment costs by using the abbreviated injury score (AIS). Using our model, the expected medical treatment costs for crash injuries to various body regions and of different severities can be investigated.

Methods

First, the simulation results are compared with NHTSA crash data. We used a modified kinematics simulation model that incorporates an F = E^b function as a supplement to the previous Steffan's model to obtain a more accurate acceleration history a(t). Second, head injury criteria HIC₃₆ can be calculated from a(t), and we use the injury probability P as a function of HIC_36, as proposed by Kuppa, to obtain the injury risk function for various AIS values. Third, medical treatment cost models for various AIS values can be calculated by using a regression cost model with real world data. Finally, the injury risk function and medical treatment cost models are linked through AIS values. We establish an integrated methodology and predict medical costs and car safety data using real world police reports, medical treatment costs, and laboratory simulation results.

Results

Using head injuries in frontal crashes as an example, we focus on simulation parameters for different vehicle models, with and without airbags. We specifically examine impact closing speed, Delta-V, and impact directions.

Conclusion

Simulation results can be used to supplement insufficient real crash data, in particular ΔV, and injury risk results from police crash reports.

Impact on industry

The proposed integrated methodology may provide the vehicle industry with a new safety assessment method. Real crash data coupling provides consumers with more realistic and applicable information.     

液相化学处理MBBR填料对城市污水厂尾水深度脱氮的影响

为进一步提高移动床生物膜反应器(MBBR)中普通聚乙烯(PE)填料对城市污水处理厂尾水中NO₃^--N的去除能力,采用液相化学处理法对PE进行改性,并对其反硝化深度脱氮效能进行研究。结果表明：改性聚乙烯(MPE)填料的静态接触角为75.5°,与PE相比降低了26.6%;扫描电镜显示,MPE与PE相比表面结构粗糙度增强;能谱及红外光谱分析表明,MPE表面氧元素含量及结构都发生了变化;MPE填料的MBBR反硝化能力与PE相比得到了明显提高,当进水NO₃^--N和TN浓度分别为(8.5±1.5)和(14.3±2.1) mg/L时,MPE填料的MBBR对NO₃^--N和TN的平均去除率分别为(75.2±7.0)%和(56.5±10.7)%,与PE相比分别提高了20.8%和58.1%。     

三维电极电解硝基苯废水处理实验研究

以涂膜活性炭-活性炭为填充粒子,对三维电极电解硝基苯废水进行了研究。通过实验探讨了投盐量、槽电压、主电极间距、反应时间及初始浓度对电解硝基苯废水的影响。结果表明,三维电极在电极间距为9mm、槽电压为20V、硫酸钠投加量为1.5g/L、pH值为6、电解时间为90min的条件下,硝基苯去除率可达90%以上。在三维电极电解作用下,硝基苯转化为可生化和低毒的苯胺,苯胺在三维电极电解作用下还可以得到进一步的降解。     

改性纤维球在油田污水处理中的应用

纤维球过滤可充分发挥出滤料深层的截污能力。介绍了改性纤维球滤料的技术要求,在使用过程中主要存在的几个问题,改性纤维球过滤器的结构及特点,在油田污水处理中的现场应用情况。试验证明,经50%互溶剂+2%表面活性剂+2%烧碱清洗后,改性纤维球滤料颜色变为灰白,纤维之间松散,不存在粘结现象,清洗较为彻底。     

Evaluation of the technoeconomic feasibility of electrochemical hydrogen peroxide production for decentralized water treatment

• Gas diffusion electrode (GDE) is a suitable setup for practical water treatment. • Electrochemical H₂O₂ production is an economically competitive technology. • High current efficiency of H₂O₂ production was obtained with GDE at 5–400 mA/cm². • GDE maintained high stability for H₂O₂ production for ~1000 h. • Electro-generation of H₂O₂ enhances ibuprofen removal in an E-peroxone process. This study evaluated the feasibility of electrochemical hydrogen peroxide (H₂O₂) production with gas diffusion electrode (GDE) for decentralized water treatment. Carbon black-polytetrafluoroethylene GDEs were prepared and tested in a continuous flow electrochemical cell for H₂O₂ production from oxygen reduction. Results showed that because of the effective oxygen transfer in GDEs, the electrode maintained high apparent current efficiencies (ACEs,>80%) for H₂O₂ production over a wide current density range of 5–400 mA/cm², and H₂O₂ production rates as high as ~202 mg/h/cm² could be obtained. Long-term stability test showed that the GDE maintained high ACEs (>85%) and low energy consumption (<10 kWh/kg H₂O₂) for H₂O₂ production for 42 d (~1000 h). However, the ACEs then decreased to ~70% in the following 4 days because water flooding of GDE pores considerably impeded oxygen transport at the late stage of the trial. Based on an electrode lifetime of 46 days, the overall cost for H₂O₂ production was estimated to be ~0.88 $/kg H₂O₂, including an electricity cost of 0.61 $/kg and an electrode capital cost of 0.27 $/kg. With a 9 cm² GDE and 40 mA/cm² current density, ~2–4 mg/L of H₂O₂ could be produced on site for the electro-peroxone treatment of a 1.2 m³/d groundwater flow, which considerably enhanced ibuprofen abatement compared with ozonation alone (~43%–59% vs. 7%). These findings suggest that electrochemical H₂O₂ production with GDEs holds great promise for the development of compact treatment technologies for decentralized water treatment at a household and community level.     

RuO2-IrO2/Ti阳极电催化降解偶氮染料甲基橙模拟废水

以自制Ti基RuO2-IrO2镀层形稳电极为阳极,采用电催化氧化处理偶氮染料甲基橙模拟废水。以硫酸钠为支持电解质,在自然pH条件下分别考察了电解时间、电极间距、电流密度和电解质浓度等因素对甲基橙去除率的影响,并分析其原因。实验结果表明,在自然pH、电极间距为1.0 cm、电流密度为30.0 mA/cm2、电解质硫酸钠浓度为20.0 g/L、电解1.0 h,甲基橙去除率高达90.0%以上。 因此,电催化氧化法作为一种高效、简便的染料废水处理技术,具有一定的应用潜力。     

Science and the Consequences of Mistruct: Lessons from Recent GM Controversies

In 2001, it was announced thattransgenic DNA had introgressed intotraditional strains of maize in Mexico. Acontroversy erupted and raged throughout 2001and 2002. This episode represents an acutebreakdown in scientific discourse. Given thestakes in the genetically modified organismdebate, a breakdown in scientific discourse isalarming. The following inquiry looks into thecauses of this breakdown. Ultimately, it willbe argued that the underlying problem is thecurrent institutional structure of science,particularly in the United States. If thediagnosis is correct, then the proper course oftreatment is to pursue a program ofinstitutional reconstruction.